Seconds versus milliseconds
The tool can interpret either unit explicitly, preventing a 13-digit millisecond timestamp from being mistaken for seconds.
Developer Tools · Local processing
Unix Timestamp Converter
Convert Unix seconds or milliseconds to readable dates and back again.
Seconds or milliseconds
Unix Timestamp Converter
Inputs and results stay in this page and are not sent to any server.
Converted values
The practical guide
Translate accurately between epoch numbers and human dates.
Unix time counts elapsed units since 1970-01-01 00:00:00 UTC; confusion between seconds and milliseconds is the most common conversion mistake.
UTC, local, and ISO views
One instant can be displayed in UTC, your browser time zone, and ISO 8601 without changing the underlying moment.
Date to epoch
Choose a date and time and convert it back to a Unix value for logs, APIs, tokens, and database fields.
Privacy by architecture
Your files and tool inputs stay in your browser.
The selected files, inputs, settings, and outputs are processed in this page and are not uploaded to any server.
Questions, answered
Frequently asked questions
What is the Unix epoch?
It is 1970-01-01 00:00:00 UTC, the reference instant for Unix timestamps.
How can I tell seconds from milliseconds?
Modern second timestamps are usually 10 digits; millisecond timestamps are usually 13, though explicit context is best.
Why does local time differ from UTC?
Your browser applies the device time-zone offset and daylight-saving rules to the same instant.
Can this explain JWT dates?
Yes. JWT time claims commonly use Unix seconds; JWT Decoder can expose the claims first.